The present invention relates to a large rectangular baler and, more specifically, relates to a drive and control system for such a baler.
The power systems for large rectangular balers typically include mechanical drives including gear transmissions and shafts for transferring power from a power take-off of a tractor to drive the various functions of the baler such as the pick-up, pre-charge chamber packer, charge stuffer, plunger, needles and knotters. The speeds at which those of these functions that deal with the delivery of crop to the baling chamber are driven, with respect to each other, is pre-selected and designed into the baler by the selection of the gearing. This has the drawback that there is no way to easily adapt the operation of the baler to different crops or changing crop conditions as is desired for more efficient operation. For example, it might be desired to operate the pick-up and/or packer at a slower or faster speed, depending on whether the crop windrow is light or heavy or the crop itself is relatively dry and brittle or somewhat damp and tough, or depending upon the speed at which the baler is towed. This ability has the benefit of being able to handle the crop in a gentler manner which is especially helpful in reducing leaf loss when baling alfalfa, for example, and to reduce the possibilities of plugging the baler.
U.S. Pat. Nos. 6,161,368; 6,073,426 and 5,894,718 disclose various large rectangular baler control systems for mechanically driven balers which address crop feeding concerns, with the ""718 patent disclosing an embodiment including a planetary transmission with which an electric or hydraulic motor is associated so as to be able to change the drive speed and/or direction, however, this speed and/or direction change affects the entire drive system, which may not be desirable.
According to the present invention there is provided an improved control system for a large rectangular baler.
An object of the invention is to provide a large rectangular baler control system including various drives constructed for being driven and controlled independently of one another for achieving operational efficiency of the baler.
A more specific object of the invention is to provide a large rectangular control system wherein the speed of the pick-up and/or packer arrangements can be varied at will without affecting the speed of operation of any other driven function.
Yet another object of the invention is to provide a large rectangular baler having independently controlled, hydraulic drive components for supplying power to all powered functions of the baler.
A more specific object of the invention is to use an electronic control unit capable of storing desired function values and for receiving feedback signals from controlled functions so that signals for operating control valves of the various hydraulic functions may continuously take into account the feedback signals for achieving the desired function value.